This invention relates to an automatic force generating and control system and, in particular, a hydraulic system for an automatic force generating and control system.
As exercise is becoming an increasingly important part of our daily routine, the demand for quality exercise machinery has become more pronounced. A particular focus for this demand centers on weight lifting machines that enable a user to achieve a total workout in a small amount of space.
Because many users have a limited amount of space in their own homes or apartments or, for that matter, at their exercise facilities, those users must be concerned with locating as much equipment as possible into smaller spaces. The attainment of these objectives poses certain problems when examining currently available exercise devices.
First, the compact designs, such as the stacked-weight system, employ cable connected weights that move along rails or bars. When more than one user is exercising, however, the weights will often drop suddenly causing the device to jerk and move. Those movements in the weights will often disturb the concentration of others, and occasionally result in injuries.
An additional disadvantage to the stacked-weight system is its lack of flexibility. Each station in such a device is primarily restricted to one or possibly two exercises. To work out the entire body, therefore, a user must rotate around to multiple stations. A total workout thus requires between eight to ten changes of location. To pace his/her workout accordingly the user must be assured that these stations remain free. When the universal machine is crowded with multiple users, such a workout can be difficult, if not impossible.
A further problem with stacked-weight systems is the generation of force on the return stroke. Stacked and free weight systems do not allow the return force to be set substantially higher than the force setting for the initial stroke. However, the muscoskeletal system yields more effective results from the point of strength gain when a higher force setting is set on the return stroke. Accordingly, conventional resistance machines using dead weights have an inherent design deficiency from the perspective of exercise efficiency.
A further disadvantage of the current exercise equipment is their lack of ability to customize the start and finish of an exercise stroke to the physical properties of the user. Specifically, the current machines are designed for one individual of a particular size. Larger individuals may be cramped while smaller individuals may be strained and perhaps totally unable to position themselves properly with respect to the equipment. Further, the start point for each exercise cannot be varied. Thus, each user is required to start the exercise stroke at the same start point regardless of whether this start point is comfortable. This enforced uniformity may injure or unnecessarily tire the user because the user may be required to exercise during some portion of the stroke which is not appropriate for the user's particular physique. Conventional weight machines do not allow the user to configure the machine to his/her individual physique and move the equipment under minor resistance to the start position most comfortable to the user before initiating resistance to movement.
A further disadvantage to the present weight lifting systems is their lack of personalized control. With the advent of computers and electronic control systems, there exists a need for a progressive resistance system that can store the force profiles of its users and tailor the exercise routines in accordance with those profiles. Thus, the person who wishes to use a machine for keeping count of his or her repetitions, for calculating a progressively challenging regime, or for visually and audibly prompting his/her exercises, can be served by a machine that takes advantage of these technologies.
An additional need by users of weight lifting systems is motivation. Over the course of a workout, the user needs a way to set exercise goals and providing motivational feedback messages. Goals take the form of allowing the user to set work-out targets that are both short term and long term in nature. Feedback can include visual indications of the workout that allow the user to track his/her range of motion, clock the length of the workout, and provide cumulative ratings of the exercise results. Feedback can also include audio motivation such as counting repetitions, audio precautions, printouts of various exercise related data, and congratulatory statements.
Finally, there is an important need to provide safety for the exerciser. A free weight system relies on an extra person to "spot" the weight lifter. If the user is alone, however, he often risks injury. Thus, a need exists for a system that contains safety features without demanding the presence of an extra person. Moreover, there is a need for a safety device which prevents children or unauthorized people from using the system without permission.